The structure of the conventional rotary compressor as shown in FIGS. 4 and 5 is constituted such that a revolution shaft 1 driven by a motor 10 is revolved; an eccentrically installed roller 11 revolves within a cylinder 12; a vane 13 is installed in such a manner as to move up and down in accordance with the revolutions of the roller 11 in order to momentarily form spaces between the wall of the cylinder 12 and the eccentric roller 11; the space is separated into a suction room 14 and a compressing room 15 by means of the vane 13; the gas is sucked into the suction room 14 through an inlet hole 16; and the gas is compressed in the compressing room 15 to discharge the compressed gas through a discharge hole 17, thereby forming a cylinder stroke, and forming circulating cycles through the repetitions of the strokes.
The conventional rotary compressor constituted as above is assembled in such a manner that; the revolution shaft 1 is inserted into the centre hole of a main bearing 2; the enccentric roller 11 is fitted from the side of the leading end of the shaft 1; the cylinder 12 is sub-assembled to the main bearing 2 as shown in FIG. 6; in this state, the clearance between the eccentric roller 11 and the cylinder 12 is checked at each angular position by rotating the shaft 2; and then, the cylinder 12 is fastened to the main bearing 2 by means of a securing bolt 18.
However, in such a conventional rotary compressor, the cylinder and the main bearing are formed in separate components, and in a state with the cylinder and the main bearing sub-assembled, the clearance between the cylinder and the eccentric roller has to be adjusted by rotating the eccentric roller.
But the tolerance for the dimension of the clearance is so very fastidious as to have to come within several micrometers, and therefore, there is the disadvantage that the assembling is difficult, and that the assembling time is extended. Further, after assembling between the cylinder and the main bearing through the fastidious adjustment, biased forces are acted due to the difference of the pressures acting on the compressing room and the suction room during the long use of the compressor, and therefore, the position of the fastening bolt can displace little by little. With the result that the clearance between the cylinder and the eccentric roller is varied and that gas is leaked through the slit thus formed, the efficiency of the compressor can be deteriorated.
Further, in the case where the displacement of the cylinder is severe, an excessive load is imposed on the cpmpressor, to such an extent that the operation of the compressor is stopped.